1. Field of Invention
This invention relates to an optoelectronic coupling element and method for its manufacture, and more particularly this invention relates to an optoelectronic coupling element including a light wave guide, semiconductor light transducer and a microlens as an optic coupling device.
2. Description of Related Art
U.S. Pat. No. 4,741,796 discloses an optoelectronic coupling element and a method for its production. Some of the technical problems associated to combining the components of coupling elements are discussed in this application.
In receiver and transmission systems using light wave guides, optical lenses are used to couple a semiconductor component to a light wave guide so that light can be transferred between the component and light wave guide. The coupling of semiconductor components and light wave guides gives rise to a number of problems. For example: the lens, semiconductor component and light wave guide must be positioned relative to each other such that their positions are within a tolerance range of 1 micrometer; the lens cannot be easily adjusted for purposes of obtaining optimal coupling; the performance of the semiconductor component can be impaired due to effects such as mechanical deformation; and the small size of the components (lens diameters between 100 and 500 micrometers) inhibits cost-effective mass production.
Various methods have been employed for mounting the lens in an optoelectronic coupling element. For example, an optical lens can be grown directly on a semiconductor chip, an optical lens can be fastened directly on a semiconductor chip, and a semiconductor chip can be mounted in a housing with a lens cap. These methods have a disadvantage in that no defined distances between the semiconductor chip and the optical lens are settable, thus the tolerances held on the location of the optical lens are relatively large.